The NIH Pediatric Allergy Clinic continues to provide residents in the NIAID Allergy and Immunology Clinical Fellowship Program with medical training and continuity clinic experience in pediatric allergic diseases including asthma, allergic rhinitis, food allergy, atopic dermatitis and urticaria. During the past fiscal year, patient care visits exceeded 500, with a total accrual of 220 new patients. The recent establishment of the allergen immunotherapy clinic has provided increased clinical experience and therapeutic value to the patients.[unreadable] [unreadable] In addition to standard diagnostic testing for allergic diseases, which includes skin prick testing, radioallergosorbent (RAST) testing, patch testing and pulmonary function testing, the clinic has integrated other modalities in the evaluation of children with allergic diseases. Acoustic rhinometry, a non-invasive sound-based tool that measures nasal volume is currently used to objectively assess nasal obstruction and response to therapy. In the evaluation of lung function, impulse oscillometry, a non-invasive, non-effort dependant technique that measures lung resistance and elasticity, is being used in conjunction with standard pulmonary function testing in older children and by itself in infants as young as two years old. A manuscript reviewing the clinical application of impulse oscillometry in pediatric patients with asthma is being prepared for publication. To further promote clinical educational resources, pediatric allergy staff members this year published ab aarticle entitled "Office Based Management of Urticaria" in the American Journal of Medicine and a book chapter entitled "The Immunological Basis of Non-IgE-Mediated Food reactions" in Food Allergy: Adverse Reactions to Food and Food Additives. [unreadable] [unreadable] Through consultation with the NHLBI pulmonology service, exercise challenge pulmonary function testing has been performed. In conjunction with other investigators in the LAD, expired breath condensate and exhaled nitric oxide measurements has been obtained for diagnostic and research purposes.[unreadable] [unreadable] Research blood is collected for screening laboratory studies, to measure markers of allergic diseases, to develop approaches to culture mast cells from blood, and to determine cytokine and signaling profiles. In particular, serum tryptase levels were measured in 44 non-atopic and 153 atopic clinic patients. Median and range tryptase levels for non-atopics were (3.44, 1.2-7.3) and (3.56, <1.0-18.8) for atopics. The analysis further compared tryptase levels in atopic and non-atopic children with respect, gender, age, total IgE, and atopic dermatitis status. There was no significant difference in baseline serum tryptase levels between atopic and non-atopic children. Among the atopic children, there was a statistically significant association of tryptase with gender but not with total IgE or eczema status.[unreadable] [unreadable] Patient documentation for communication with referring physicians and for longitudinal analysis is entered into CRIMSON, the NIAID database system.